Beer Aftertaste Improved by Reducing Astringent Substances in the Barley Malt with Subcritical Water Treatment

Astringent substances derived from acrospires of barley malt can be reduced by treatment with subcritical water. Crude hordatine β-d-glucopyranoside, identified as one of the astringent substances in barley malt, was shown to be reduced by about 80% under subcritical conditions. It was confirmed that the astringent substances in barley malt were reduced by the treatment of barley malt at various subcritical conditions. Beer was brewed using malt treated with subcritical water, and the astringency and the quantities of astringent substances were evaluated. The astringent components and the aftertaste in the beer were clearly reduced, and the reduction of astringent components in barley malt by treatment with subcritical water was shown to be a good way to control beer aftertaste.